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QAbstractSeries Class

The QAbstractSeries class is a base class for all Qt Chart series. More...

Header: #include <QAbstractSeries>
Instantiated By: AbstractSeries
Inherits: QObject
Inherited By:

QAbstractBarSeries, QAreaSeries, QBoxPlotSeries, QCandlestickSeries, QPieSeries, and QXYSeries

Public Types

enum SeriesType { SeriesTypeLine, SeriesTypeArea, SeriesTypeBar, SeriesTypeStackedBar, SeriesTypePercentBar, …, SeriesTypeCandlestick }

Properties

Public Functions

virtual ~QAbstractSeries()
bool attachAxis(QAbstractAxis *axis)
QList<QAbstractAxis *> attachedAxes()
QChart *chart() const
bool detachAxis(QAbstractAxis *axis)
void hide()
bool isVisible() const
QString name() const
qreal opacity() const
void setName(const QString &name)
void setOpacity(qreal opacity)
void setUseOpenGL(bool enable = true)
void setVisible(bool visible = true)
void show()
virtual QAbstractSeries::SeriesType type() const = 0
bool useOpenGL() const

Signals

void nameChanged()
void opacityChanged()
void useOpenGLChanged()
void visibleChanged()

Detailed Description

Usually, the series type specific inherited classes are used instead of the base class.

See also QXYSeries, QLineSeries, QSplineSeries, QScatterSeries, QAreaSeries, QAbstractBarSeries, QBarSeries, QStackedBarSeries, QPercentBarSeries, QHorizontalBarSeries, QHorizontalStackedBarSeries, QHorizontalPercentBarSeries, and QPieSeries.

Member Type Documentation

enum QAbstractSeries::SeriesType

This enum describes the type of the series.

ConstantValueDescription
QAbstractSeries::SeriesTypeLine0A line chart.
QAbstractSeries::SeriesTypeArea1An area chart.
QAbstractSeries::SeriesTypeBar2A vertical bar chart.
QAbstractSeries::SeriesTypeStackedBar3A vertical stacked bar chart.
QAbstractSeries::SeriesTypePercentBar4A vertical percent bar chart.
QAbstractSeries::SeriesTypePie5A pie chart.
QAbstractSeries::SeriesTypeScatter6A scatter chart.
QAbstractSeries::SeriesTypeSpline7A spline chart.
QAbstractSeries::SeriesTypeHorizontalBar8A horizontal bar chart.
QAbstractSeries::SeriesTypeHorizontalStackedBar9A horizontal stacked bar chart.
QAbstractSeries::SeriesTypeHorizontalPercentBar10A horizontal percent bar chart.
QAbstractSeries::SeriesTypeBoxPlot11A box plot chart.
QAbstractSeries::SeriesTypeCandlestick12A candlestick chart.

Property Documentation

name : QString

This property holds the name of the series.

The name is displayed in the legend for the series and it supports HTML formatting.

Access functions:

QString name() const
void setName(const QString &name)

Notifier signal:

void nameChanged()

opacity : qreal

This property holds the opacity of the series.

By default, the opacity is 1.0. The valid values range from 0.0 (transparent) to 1.0 (opaque).

Access functions:

qreal opacity() const
void setOpacity(qreal opacity)

Notifier signal:

void opacityChanged()

type : const SeriesType

This property holds the type of the series.

Access functions:

virtual QAbstractSeries::SeriesType type() const = 0

useOpenGL : bool

Specifies whether or not drawing the series is accelerated by using OpenGL.

Acceleration using OpenGL is supported only for QLineSeries and QScatterSeries. A line series used as an edge series for QAreaSeries cannot use OpenGL acceleration. When a chart contains any series that are drawn with OpenGL, a transparent QOpenGLWidget is created on top of the chart plot area. The accelerated series are not drawn on the underlying QGraphicsView, but are instead drawn on the created QOpenGLWidget.

Performance gained from using OpenGL to accelerate series drawing depends on the underlying hardware, but in most cases it is significant. For example, on a standard desktop computer, enabling OpenGL acceleration for a series typically allows rendering at least a hundred times more points without reduction on the frame rate. Chart size also has less effect on the frame rate.

The OpenGL acceleration of series drawing is meant for use cases that need fast drawing of large numbers of points. It is optimized for efficiency, and therefore the series using it lack support for many features available to non-accelerated series:

  • Series animations are not supported for accelerated series.
  • Point labels are not supported for accelerated series.
  • Pen styles and marker shapes are ignored for accelerated series. Only solid lines and plain scatter dots are supported. The scatter dots may be circular or rectangular, depending on the underlying graphics hardware and drivers.
  • Polar charts do not support accelerated series.
  • Enabling chart drop shadow or using transparent chart background color is not recommended when using accelerated series, as that can slow the frame rate down significantly.

These additional restrictions stem from the fact that the accelerated series is drawn on a separate widget on top of the chart:

  • If you draw any graphics items on top of a chart containing an accelerated series, the accelerated series is drawn over those items.
  • To enable QOpenGLWidget to be partially transparent, it needs to be stacked on top of all other widgets. This means you cannot have other widgets partially covering the chart when using accelerated series.
  • Accelerated series are not supported for use cases where the graphics scene has more than one graphics view attached to it.
  • Accelerated series are not supported for use cases where the chart has non-default geometry. For example, adding transforms to the graphics view causes the accelerated series to be drawn in an incorrect position related to the chart.

The default value is false.

Access functions:

bool useOpenGL() const
void setUseOpenGL(bool enable = true)

Notifier signal:

void useOpenGLChanged()

visible : bool

This property holds whether the series is visible or not.

By default, true.

Access functions:

bool isVisible() const
void setVisible(bool visible = true)

Notifier signal:

void visibleChanged()

Member Function Documentation

[signal] void QAbstractSeries::nameChanged()

This signal is emitted when the series name changes.

Note: Notifier signal for property name.

[signal] void QAbstractSeries::opacityChanged()

This signal is emitted when the opacity of the series changes.

Note: Notifier signal for property opacity.

[signal] void QAbstractSeries::useOpenGLChanged()

This signal is emitted when accelerating the drawing of the series by using OpenGL is enabled or disabled.

Note: Notifier signal for property useOpenGL.

[signal] void QAbstractSeries::visibleChanged()

This signal is emitted when the series visibility changes.

Note: Notifier signal for property visible.

[virtual] QAbstractSeries::~QAbstractSeries()

Virtual destructor for the chart series.

bool QAbstractSeries::attachAxis(QAbstractAxis *axis)

Attaches the axis specified by axis to the series.

Returns true if the axis was attached successfully, false otherwise.

Note: If multiple axes of the same orientation are attached to the same series, they will have the same minimum and maximum values.

See also QChart::addAxis() and QChart::createDefaultAxes().

QList<QAbstractAxis *> QAbstractSeries::attachedAxes()

Returns the list of axes attached to the series. Usually, an x-axis and a y-axis are attached to a series, except for QPieSeries, which does not have any axes attached.

See also attachAxis() and detachAxis().

QChart *QAbstractSeries::chart() const

Returns the chart that the series belongs to.

Set automatically when the series is added to the chart, and unset when the series is removed from the chart.

bool QAbstractSeries::detachAxis(QAbstractAxis *axis)

Detaches the axis specified by axis from the series.

Returns true if the axis was detached successfully, false otherwise.

See also QChart::removeAxis().

void QAbstractSeries::hide()

Sets the visibility of the series to false.

See also setVisible() and isVisible().

void QAbstractSeries::show()

Sets the visibility of the series to true.

See also setVisible() and isVisible().

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